Fiber-optics provides high bandwidth data center interconnection (DCI) for data center networks. Existing intra-data center interconnection technologies use intensity modulation (IM) and direction detection (DD) technology. However, the existing IM-DD approach does not scale well with bandwidth growth as data consumption rises. Continuous growth in DCI bandwidth demand and consumption, for example, to support over 100 Gb/s of data transmission per wavelength using IM-DD, can be technologically challenging and expensive to implement.
Coherent optics is an alternative approach suitable for high bandwidth DCI for data center networks. However, due to the evolutionary nature of data center networks, the un-proven next generation technologies, such as those based on coherent optics, must be backward compatible with the existing technology for a large scale datacenter network. Implementing the network to be partially and seamlessly upgraded, without needing to upgrade the entire data center all at once can be both cost prohibitive and impractical. As a result, a challenge remains on how to make the coherent optics technology backward compatible with the existing IM-DD technology to better bridge the current and future technologies.